Source file src/syscall/syscall_windows.go

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Windows system calls.
     6  
     7  package syscall
     8  
     9  import (
    10  	errorspkg "errors"
    11  	"internal/asan"
    12  	"internal/bytealg"
    13  	"internal/itoa"
    14  	"internal/msan"
    15  	"internal/oserror"
    16  	"internal/race"
    17  	"runtime"
    18  	"sync"
    19  	"unsafe"
    20  )
    21  
    22  type Handle uintptr
    23  
    24  const InvalidHandle = ^Handle(0)
    25  
    26  // StringToUTF16 returns the UTF-16 encoding of the UTF-8 string s,
    27  // with a terminating NUL added. If s contains a NUL byte this
    28  // function panics instead of returning an error.
    29  //
    30  // Deprecated: Use [UTF16FromString] instead.
    31  func StringToUTF16(s string) []uint16 {
    32  	a, err := UTF16FromString(s)
    33  	if err != nil {
    34  		panic("syscall: string with NUL passed to StringToUTF16")
    35  	}
    36  	return a
    37  }
    38  
    39  // UTF16FromString returns the UTF-16 encoding of the UTF-8 string
    40  // s, with a terminating NUL added. If s contains a NUL byte at any
    41  // location, it returns (nil, [EINVAL]). Unpaired surrogates
    42  // are encoded using WTF-8.
    43  func UTF16FromString(s string) ([]uint16, error) {
    44  	if bytealg.IndexByteString(s, 0) != -1 {
    45  		return nil, EINVAL
    46  	}
    47  	// Valid UTF-8 characters between 1 and 3 bytes require one uint16.
    48  	// Valid UTF-8 characters of 4 bytes require two uint16.
    49  	// Bytes with invalid UTF-8 encoding require maximum one uint16 per byte.
    50  	// So the number of UTF-8 code units (len(s)) is always greater or
    51  	// equal than the number of UTF-16 code units.
    52  	// Also account for the terminating NUL character.
    53  	buf := make([]uint16, 0, len(s)+1)
    54  	buf = encodeWTF16(s, buf)
    55  	return append(buf, 0), nil
    56  }
    57  
    58  // UTF16ToString returns the UTF-8 encoding of the UTF-16 sequence s,
    59  // with a terminating NUL removed. Unpaired surrogates are decoded
    60  // using WTF-8 instead of UTF-8 encoding.
    61  func UTF16ToString(s []uint16) string {
    62  	maxLen := 0
    63  	for i, v := range s {
    64  		if v == 0 {
    65  			s = s[0:i]
    66  			break
    67  		}
    68  		switch {
    69  		case v <= rune1Max:
    70  			maxLen += 1
    71  		case v <= rune2Max:
    72  			maxLen += 2
    73  		default:
    74  			// r is a non-surrogate that decodes to 3 bytes,
    75  			// or is an unpaired surrogate (also 3 bytes in WTF-8),
    76  			// or is one half of a valid surrogate pair.
    77  			// If it is half of a pair, we will add 3 for the second surrogate
    78  			// (total of 6) and overestimate by 2 bytes for the pair,
    79  			// since the resulting rune only requires 4 bytes.
    80  			maxLen += 3
    81  		}
    82  	}
    83  	buf := decodeWTF16(s, make([]byte, 0, maxLen))
    84  	return unsafe.String(unsafe.SliceData(buf), len(buf))
    85  }
    86  
    87  // utf16PtrToString is like UTF16ToString, but takes *uint16
    88  // as a parameter instead of []uint16.
    89  func utf16PtrToString(p *uint16) string {
    90  	if p == nil {
    91  		return ""
    92  	}
    93  	end := unsafe.Pointer(p)
    94  	n := 0
    95  	for *(*uint16)(end) != 0 {
    96  		end = unsafe.Pointer(uintptr(end) + unsafe.Sizeof(*p))
    97  		n++
    98  	}
    99  	return UTF16ToString(unsafe.Slice(p, n))
   100  }
   101  
   102  // StringToUTF16Ptr returns pointer to the UTF-16 encoding of
   103  // the UTF-8 string s, with a terminating NUL added. If s
   104  // contains a NUL byte this function panics instead of
   105  // returning an error.
   106  //
   107  // Deprecated: Use [UTF16PtrFromString] instead.
   108  func StringToUTF16Ptr(s string) *uint16 { return &StringToUTF16(s)[0] }
   109  
   110  // UTF16PtrFromString returns pointer to the UTF-16 encoding of
   111  // the UTF-8 string s, with a terminating NUL added. If s
   112  // contains a NUL byte at any location, it returns (nil, EINVAL).
   113  // Unpaired surrogates are encoded using WTF-8.
   114  func UTF16PtrFromString(s string) (*uint16, error) {
   115  	a, err := UTF16FromString(s)
   116  	if err != nil {
   117  		return nil, err
   118  	}
   119  	return &a[0], nil
   120  }
   121  
   122  // Errno is the Windows error number.
   123  //
   124  // Errno values can be tested against error values using [errors.Is].
   125  // For example:
   126  //
   127  //	_, _, err := syscall.Syscall(...)
   128  //	if errors.Is(err, fs.ErrNotExist) ...
   129  type Errno uintptr
   130  
   131  func langid(pri, sub uint16) uint32 { return uint32(sub)<<10 | uint32(pri) }
   132  
   133  // FormatMessage is deprecated (msgsrc should be uintptr, not uint32, but can
   134  // not be changed due to the Go 1 compatibility guarantee).
   135  //
   136  // Deprecated: Use FormatMessage from golang.org/x/sys/windows instead.
   137  func FormatMessage(flags uint32, msgsrc uint32, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) {
   138  	return formatMessage(flags, uintptr(msgsrc), msgid, langid, buf, args)
   139  }
   140  
   141  func (e Errno) Error() string {
   142  	// deal with special go errors
   143  	idx := int(e - APPLICATION_ERROR)
   144  	if 0 <= idx && idx < len(errors) {
   145  		return errors[idx]
   146  	}
   147  	// ask windows for the remaining errors
   148  	var flags uint32 = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY | FORMAT_MESSAGE_IGNORE_INSERTS
   149  	b := make([]uint16, 300)
   150  	n, err := formatMessage(flags, 0, uint32(e), langid(LANG_ENGLISH, SUBLANG_ENGLISH_US), b, nil)
   151  	if err != nil {
   152  		n, err = formatMessage(flags, 0, uint32(e), 0, b, nil)
   153  		if err != nil {
   154  			return "winapi error #" + itoa.Itoa(int(e))
   155  		}
   156  	}
   157  	// trim terminating \r and \n
   158  	for ; n > 0 && (b[n-1] == '\n' || b[n-1] == '\r'); n-- {
   159  	}
   160  	return UTF16ToString(b[:n])
   161  }
   162  
   163  const (
   164  	_ERROR_NOT_ENOUGH_MEMORY    = Errno(8)
   165  	_ERROR_NOT_SUPPORTED        = Errno(50)
   166  	_ERROR_BAD_NETPATH          = Errno(53)
   167  	_ERROR_CALL_NOT_IMPLEMENTED = Errno(120)
   168  )
   169  
   170  func (e Errno) Is(target error) bool {
   171  	switch target {
   172  	case oserror.ErrPermission:
   173  		return e == ERROR_ACCESS_DENIED ||
   174  			e == EACCES ||
   175  			e == EPERM
   176  	case oserror.ErrExist:
   177  		return e == ERROR_ALREADY_EXISTS ||
   178  			e == ERROR_DIR_NOT_EMPTY ||
   179  			e == ERROR_FILE_EXISTS ||
   180  			e == EEXIST ||
   181  			e == ENOTEMPTY
   182  	case oserror.ErrNotExist:
   183  		return e == ERROR_FILE_NOT_FOUND ||
   184  			e == _ERROR_BAD_NETPATH ||
   185  			e == ERROR_PATH_NOT_FOUND ||
   186  			e == ENOENT
   187  	case errorspkg.ErrUnsupported:
   188  		return e == _ERROR_NOT_SUPPORTED ||
   189  			e == _ERROR_CALL_NOT_IMPLEMENTED ||
   190  			e == ENOSYS ||
   191  			e == ENOTSUP ||
   192  			e == EOPNOTSUPP ||
   193  			e == EWINDOWS
   194  	}
   195  	return false
   196  }
   197  
   198  func (e Errno) Temporary() bool {
   199  	return e == EINTR || e == EMFILE || e.Timeout()
   200  }
   201  
   202  func (e Errno) Timeout() bool {
   203  	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
   204  }
   205  
   206  // Implemented in runtime/syscall_windows.go.
   207  func compileCallback(fn any, cleanstack bool) uintptr
   208  
   209  // NewCallback converts a Go function to a function pointer conforming to the stdcall calling convention.
   210  // This is useful when interoperating with Windows code requiring callbacks.
   211  // The argument is expected to be a function with one uintptr-sized result. The function must not have arguments with size larger than the size of uintptr.
   212  // Only a limited number of callbacks may be created in a single Go process, and any memory allocated
   213  // for these callbacks is never released.
   214  // Between NewCallback and NewCallbackCDecl, at least 1024 callbacks can always be created.
   215  func NewCallback(fn any) uintptr {
   216  	return compileCallback(fn, true)
   217  }
   218  
   219  // NewCallbackCDecl converts a Go function to a function pointer conforming to the cdecl calling convention.
   220  // This is useful when interoperating with Windows code requiring callbacks.
   221  // The argument is expected to be a function with one uintptr-sized result. The function must not have arguments with size larger than the size of uintptr.
   222  // Only a limited number of callbacks may be created in a single Go process, and any memory allocated
   223  // for these callbacks is never released.
   224  // Between NewCallback and NewCallbackCDecl, at least 1024 callbacks can always be created.
   225  func NewCallbackCDecl(fn any) uintptr {
   226  	return compileCallback(fn, false)
   227  }
   228  
   229  // windows api calls
   230  
   231  //sys	GetLastError() (lasterr error)
   232  //sys	LoadLibrary(libname string) (handle Handle, err error) = LoadLibraryW
   233  //sys	FreeLibrary(handle Handle) (err error)
   234  //sys	GetProcAddress(module Handle, procname string) (proc uintptr, err error)
   235  //sys	GetVersion() (ver uint32, err error)
   236  //sys	formatMessage(flags uint32, msgsrc uintptr, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) = FormatMessageW
   237  //sys	ExitProcess(exitcode uint32)
   238  //sys	createFile(name *uint16, access uint32, mode uint32, sa *SecurityAttributes, createmode uint32, attrs uint32, templatefile int32) (handle Handle, err error) [failretval == InvalidHandle || e1 == ERROR_ALREADY_EXISTS ] = CreateFileW
   239  //sys	readFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error) = ReadFile
   240  //sys	writeFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error) = WriteFile
   241  //sys	SetFilePointer(handle Handle, lowoffset int32, highoffsetptr *int32, whence uint32) (newlowoffset uint32, err error) [failretval==0xffffffff]
   242  //sys	CloseHandle(handle Handle) (err error)
   243  //sys	GetStdHandle(stdhandle int) (handle Handle, err error) [failretval==InvalidHandle]
   244  //sys	findFirstFile1(name *uint16, data *win32finddata1) (handle Handle, err error) [failretval==InvalidHandle] = FindFirstFileW
   245  //sys	findNextFile1(handle Handle, data *win32finddata1) (err error) = FindNextFileW
   246  //sys	FindClose(handle Handle) (err error)
   247  //sys	GetFileInformationByHandle(handle Handle, data *ByHandleFileInformation) (err error)
   248  //sys	GetCurrentDirectory(buflen uint32, buf *uint16) (n uint32, err error) = GetCurrentDirectoryW
   249  //sys	SetCurrentDirectory(path *uint16) (err error) = SetCurrentDirectoryW
   250  //sys	CreateDirectory(path *uint16, sa *SecurityAttributes) (err error) = CreateDirectoryW
   251  //sys	RemoveDirectory(path *uint16) (err error) = RemoveDirectoryW
   252  //sys	DeleteFile(path *uint16) (err error) = DeleteFileW
   253  //sys	MoveFile(from *uint16, to *uint16) (err error) = MoveFileW
   254  //sys	GetComputerName(buf *uint16, n *uint32) (err error) = GetComputerNameW
   255  //sys	SetEndOfFile(handle Handle) (err error)
   256  //sys	GetSystemTimeAsFileTime(time *Filetime)
   257  //sys	GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) [failretval==0xffffffff]
   258  //sys	createIoCompletionPort(filehandle Handle, cphandle Handle, key uintptr, threadcnt uint32) (handle Handle, err error) = CreateIoCompletionPort
   259  //sys	getQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uintptr, overlapped **Overlapped, timeout uint32) (err error) = GetQueuedCompletionStatus
   260  //sys	postQueuedCompletionStatus(cphandle Handle, qty uint32, key uintptr, overlapped *Overlapped) (err error) = PostQueuedCompletionStatus
   261  //sys	CancelIo(s Handle) (err error)
   262  //sys	CancelIoEx(s Handle, o *Overlapped) (err error)
   263  //sys	CreateProcess(appName *uint16, commandLine *uint16, procSecurity *SecurityAttributes, threadSecurity *SecurityAttributes, inheritHandles bool, creationFlags uint32, env *uint16, currentDir *uint16, startupInfo *StartupInfo, outProcInfo *ProcessInformation) (err error) = CreateProcessW
   264  //sys	CreateProcessAsUser(token Token, appName *uint16, commandLine *uint16, procSecurity *SecurityAttributes, threadSecurity *SecurityAttributes, inheritHandles bool, creationFlags uint32, env *uint16, currentDir *uint16, startupInfo *StartupInfo, outProcInfo *ProcessInformation) (err error) = advapi32.CreateProcessAsUserW
   265  //sys	OpenProcess(da uint32, inheritHandle bool, pid uint32) (handle Handle, err error)
   266  //sys	TerminateProcess(handle Handle, exitcode uint32) (err error)
   267  //sys	GetExitCodeProcess(handle Handle, exitcode *uint32) (err error)
   268  //sys	getStartupInfo(startupInfo *StartupInfo) = GetStartupInfoW
   269  //sys	GetCurrentProcess() (pseudoHandle Handle, err error)
   270  //sys	GetProcessTimes(handle Handle, creationTime *Filetime, exitTime *Filetime, kernelTime *Filetime, userTime *Filetime) (err error)
   271  //sys	DuplicateHandle(hSourceProcessHandle Handle, hSourceHandle Handle, hTargetProcessHandle Handle, lpTargetHandle *Handle, dwDesiredAccess uint32, bInheritHandle bool, dwOptions uint32) (err error)
   272  //sys	WaitForSingleObject(handle Handle, waitMilliseconds uint32) (event uint32, err error) [failretval==0xffffffff]
   273  //sys	GetTempPath(buflen uint32, buf *uint16) (n uint32, err error) = GetTempPathW
   274  //sys	CreatePipe(readhandle *Handle, writehandle *Handle, sa *SecurityAttributes, size uint32) (err error)
   275  //sys	GetFileType(filehandle Handle) (n uint32, err error)
   276  //sys	CryptAcquireContext(provhandle *Handle, container *uint16, provider *uint16, provtype uint32, flags uint32) (err error) = advapi32.CryptAcquireContextW
   277  //sys	CryptReleaseContext(provhandle Handle, flags uint32) (err error) = advapi32.CryptReleaseContext
   278  //sys	CryptGenRandom(provhandle Handle, buflen uint32, buf *byte) (err error) = advapi32.CryptGenRandom
   279  //sys	GetEnvironmentStrings() (envs *uint16, err error) [failretval==nil] = kernel32.GetEnvironmentStringsW
   280  //sys	FreeEnvironmentStrings(envs *uint16) (err error) = kernel32.FreeEnvironmentStringsW
   281  //sys	GetEnvironmentVariable(name *uint16, buffer *uint16, size uint32) (n uint32, err error) = kernel32.GetEnvironmentVariableW
   282  //sys	SetEnvironmentVariable(name *uint16, value *uint16) (err error) = kernel32.SetEnvironmentVariableW
   283  //sys	SetFileTime(handle Handle, ctime *Filetime, atime *Filetime, wtime *Filetime) (err error)
   284  //sys	GetFileAttributes(name *uint16) (attrs uint32, err error) [failretval==INVALID_FILE_ATTRIBUTES] = kernel32.GetFileAttributesW
   285  //sys	SetFileAttributes(name *uint16, attrs uint32) (err error) = kernel32.SetFileAttributesW
   286  //sys	GetFileAttributesEx(name *uint16, level uint32, info *byte) (err error) = kernel32.GetFileAttributesExW
   287  //sys	GetCommandLine() (cmd *uint16) = kernel32.GetCommandLineW
   288  //sys	CommandLineToArgv(cmd *uint16, argc *int32) (argv *[8192]*[8192]uint16, err error) [failretval==nil] = shell32.CommandLineToArgvW
   289  //sys	LocalFree(hmem Handle) (handle Handle, err error) [failretval!=0]
   290  //sys	localAlloc(flags uint32, length uint32) (ptr uintptr, err error) = kernel32.LocalAlloc
   291  //sys	SetHandleInformation(handle Handle, mask uint32, flags uint32) (err error)
   292  //sys	FlushFileBuffers(handle Handle) (err error)
   293  //sys	GetFullPathName(path *uint16, buflen uint32, buf *uint16, fname **uint16) (n uint32, err error) = kernel32.GetFullPathNameW
   294  //sys	GetLongPathName(path *uint16, buf *uint16, buflen uint32) (n uint32, err error) = kernel32.GetLongPathNameW
   295  //sys	GetShortPathName(longpath *uint16, shortpath *uint16, buflen uint32) (n uint32, err error) = kernel32.GetShortPathNameW
   296  //sys	CreateFileMapping(fhandle Handle, sa *SecurityAttributes, prot uint32, maxSizeHigh uint32, maxSizeLow uint32, name *uint16) (handle Handle, err error) = kernel32.CreateFileMappingW
   297  //sys	MapViewOfFile(handle Handle, access uint32, offsetHigh uint32, offsetLow uint32, length uintptr) (addr uintptr, err error)
   298  //sys	UnmapViewOfFile(addr uintptr) (err error)
   299  //sys	FlushViewOfFile(addr uintptr, length uintptr) (err error)
   300  //sys	VirtualLock(addr uintptr, length uintptr) (err error)
   301  //sys	VirtualUnlock(addr uintptr, length uintptr) (err error)
   302  //sys	TransmitFile(s Handle, handle Handle, bytesToWrite uint32, bytsPerSend uint32, overlapped *Overlapped, transmitFileBuf *TransmitFileBuffers, flags uint32) (err error) = mswsock.TransmitFile
   303  //sys	ReadDirectoryChanges(handle Handle, buf *byte, buflen uint32, watchSubTree bool, mask uint32, retlen *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) = kernel32.ReadDirectoryChangesW
   304  //sys	CertOpenSystemStore(hprov Handle, name *uint16) (store Handle, err error) = crypt32.CertOpenSystemStoreW
   305  //sys   CertOpenStore(storeProvider uintptr, msgAndCertEncodingType uint32, cryptProv uintptr, flags uint32, para uintptr) (handle Handle, err error) = crypt32.CertOpenStore
   306  //sys	CertEnumCertificatesInStore(store Handle, prevContext *CertContext) (context *CertContext, err error) [failretval==nil] = crypt32.CertEnumCertificatesInStore
   307  //sys   CertAddCertificateContextToStore(store Handle, certContext *CertContext, addDisposition uint32, storeContext **CertContext) (err error) = crypt32.CertAddCertificateContextToStore
   308  //sys	CertCloseStore(store Handle, flags uint32) (err error) = crypt32.CertCloseStore
   309  //sys   CertGetCertificateChain(engine Handle, leaf *CertContext, time *Filetime, additionalStore Handle, para *CertChainPara, flags uint32, reserved uintptr, chainCtx **CertChainContext) (err error) = crypt32.CertGetCertificateChain
   310  //sys   CertFreeCertificateChain(ctx *CertChainContext) = crypt32.CertFreeCertificateChain
   311  //sys   CertCreateCertificateContext(certEncodingType uint32, certEncoded *byte, encodedLen uint32) (context *CertContext, err error) [failretval==nil] = crypt32.CertCreateCertificateContext
   312  //sys   CertFreeCertificateContext(ctx *CertContext) (err error) = crypt32.CertFreeCertificateContext
   313  //sys   CertVerifyCertificateChainPolicy(policyOID uintptr, chain *CertChainContext, para *CertChainPolicyPara, status *CertChainPolicyStatus) (err error) = crypt32.CertVerifyCertificateChainPolicy
   314  //sys	RegOpenKeyEx(key Handle, subkey *uint16, options uint32, desiredAccess uint32, result *Handle) (regerrno error) = advapi32.RegOpenKeyExW
   315  //sys	RegCloseKey(key Handle) (regerrno error) = advapi32.RegCloseKey
   316  //sys	RegQueryInfoKey(key Handle, class *uint16, classLen *uint32, reserved *uint32, subkeysLen *uint32, maxSubkeyLen *uint32, maxClassLen *uint32, valuesLen *uint32, maxValueNameLen *uint32, maxValueLen *uint32, saLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegQueryInfoKeyW
   317  //sys	regEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegEnumKeyExW
   318  //sys	RegQueryValueEx(key Handle, name *uint16, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno error) = advapi32.RegQueryValueExW
   319  //sys	getCurrentProcessId() (pid uint32) = kernel32.GetCurrentProcessId
   320  //sys	GetConsoleMode(console Handle, mode *uint32) (err error) = kernel32.GetConsoleMode
   321  //sys	WriteConsole(console Handle, buf *uint16, towrite uint32, written *uint32, reserved *byte) (err error) = kernel32.WriteConsoleW
   322  //sys	ReadConsole(console Handle, buf *uint16, toread uint32, read *uint32, inputControl *byte) (err error) = kernel32.ReadConsoleW
   323  //sys	CreateToolhelp32Snapshot(flags uint32, processId uint32) (handle Handle, err error) [failretval==InvalidHandle] = kernel32.CreateToolhelp32Snapshot
   324  //sys	Process32First(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32FirstW
   325  //sys	Process32Next(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32NextW
   326  //sys	DeviceIoControl(handle Handle, ioControlCode uint32, inBuffer *byte, inBufferSize uint32, outBuffer *byte, outBufferSize uint32, bytesReturned *uint32, overlapped *Overlapped) (err error)
   327  //sys	setFileInformationByHandle(handle Handle, fileInformationClass uint32, buf unsafe.Pointer, bufsize uint32) (err error) = kernel32.SetFileInformationByHandle
   328  // This function returns 1 byte BOOLEAN rather than the 4 byte BOOL.
   329  //sys	CreateSymbolicLink(symlinkfilename *uint16, targetfilename *uint16, flags uint32) (err error) [failretval&0xff==0] = CreateSymbolicLinkW
   330  //sys	CreateHardLink(filename *uint16, existingfilename *uint16, reserved uintptr) (err error) [failretval&0xff==0] = CreateHardLinkW
   331  //sys	initializeProcThreadAttributeList(attrlist *_PROC_THREAD_ATTRIBUTE_LIST, attrcount uint32, flags uint32, size *uintptr) (err error) = InitializeProcThreadAttributeList
   332  //sys	deleteProcThreadAttributeList(attrlist *_PROC_THREAD_ATTRIBUTE_LIST) = DeleteProcThreadAttributeList
   333  //sys	updateProcThreadAttribute(attrlist *_PROC_THREAD_ATTRIBUTE_LIST, flags uint32, attr uintptr, value unsafe.Pointer, size uintptr, prevvalue unsafe.Pointer, returnedsize *uintptr) (err error) = UpdateProcThreadAttribute
   334  //sys	getFinalPathNameByHandle(file Handle, filePath *uint16, filePathSize uint32, flags uint32) (n uint32, err error) [n == 0 || n >= filePathSize] = kernel32.GetFinalPathNameByHandleW
   335  
   336  // syscall interface implementation for other packages
   337  
   338  func makeInheritSa() *SecurityAttributes {
   339  	var sa SecurityAttributes
   340  	sa.Length = uint32(unsafe.Sizeof(sa))
   341  	sa.InheritHandle = 1
   342  	return &sa
   343  }
   344  
   345  func Open(name string, flag int, perm uint32) (fd Handle, err error) {
   346  	if len(name) == 0 {
   347  		return InvalidHandle, ERROR_FILE_NOT_FOUND
   348  	}
   349  	namep, err := UTF16PtrFromString(name)
   350  	if err != nil {
   351  		return InvalidHandle, err
   352  	}
   353  	var access uint32
   354  	switch flag & (O_RDONLY | O_WRONLY | O_RDWR) {
   355  	case O_RDONLY:
   356  		access = GENERIC_READ
   357  	case O_WRONLY:
   358  		access = GENERIC_WRITE
   359  	case O_RDWR:
   360  		access = GENERIC_READ | GENERIC_WRITE
   361  	}
   362  	if flag&O_CREAT != 0 {
   363  		access |= GENERIC_WRITE
   364  	}
   365  	if flag&O_APPEND != 0 {
   366  		// Remove GENERIC_WRITE unless O_TRUNC is set, in which case we need it to truncate the file.
   367  		// We can't just remove FILE_WRITE_DATA because GENERIC_WRITE without FILE_WRITE_DATA
   368  		// starts appending at the beginning of the file rather than at the end.
   369  		if flag&O_TRUNC == 0 {
   370  			access &^= GENERIC_WRITE
   371  		}
   372  		// Set all access rights granted by GENERIC_WRITE except for FILE_WRITE_DATA.
   373  		access |= FILE_APPEND_DATA | FILE_WRITE_ATTRIBUTES | _FILE_WRITE_EA | STANDARD_RIGHTS_WRITE | SYNCHRONIZE
   374  	}
   375  	sharemode := uint32(FILE_SHARE_READ | FILE_SHARE_WRITE)
   376  	var sa *SecurityAttributes
   377  	if flag&O_CLOEXEC == 0 {
   378  		sa = makeInheritSa()
   379  	}
   380  	// We don't use CREATE_ALWAYS, because when opening a file with
   381  	// FILE_ATTRIBUTE_READONLY these will replace an existing file
   382  	// with a new, read-only one. See https://go.dev/issue/38225.
   383  	//
   384  	// Instead, we ftruncate the file after opening when O_TRUNC is set.
   385  	var createmode uint32
   386  	switch {
   387  	case flag&(O_CREAT|O_EXCL) == (O_CREAT | O_EXCL):
   388  		createmode = CREATE_NEW
   389  	case flag&O_CREAT == O_CREAT:
   390  		createmode = OPEN_ALWAYS
   391  	default:
   392  		createmode = OPEN_EXISTING
   393  	}
   394  	var attrs uint32 = FILE_ATTRIBUTE_NORMAL
   395  	if perm&S_IWRITE == 0 {
   396  		attrs = FILE_ATTRIBUTE_READONLY
   397  	}
   398  	if flag&O_WRONLY == 0 && flag&O_RDWR == 0 {
   399  		// We might be opening or creating a directory.
   400  		// CreateFile requires FILE_FLAG_BACKUP_SEMANTICS
   401  		// to work with directories.
   402  		attrs |= FILE_FLAG_BACKUP_SEMANTICS
   403  	}
   404  	if flag&O_SYNC != 0 {
   405  		const _FILE_FLAG_WRITE_THROUGH = 0x80000000
   406  		attrs |= _FILE_FLAG_WRITE_THROUGH
   407  	}
   408  	h, err := createFile(namep, access, sharemode, sa, createmode, attrs, 0)
   409  	if h == InvalidHandle {
   410  		if err == ERROR_ACCESS_DENIED && (flag&O_WRONLY != 0 || flag&O_RDWR != 0) {
   411  			// We should return EISDIR when we are trying to open a directory with write access.
   412  			fa, e1 := GetFileAttributes(namep)
   413  			if e1 == nil && fa&FILE_ATTRIBUTE_DIRECTORY != 0 {
   414  				err = EISDIR
   415  			}
   416  		}
   417  		return h, err
   418  	}
   419  	// Ignore O_TRUNC if the file has just been created.
   420  	if flag&O_TRUNC == O_TRUNC &&
   421  		(createmode == OPEN_EXISTING || (createmode == OPEN_ALWAYS && err == ERROR_ALREADY_EXISTS)) {
   422  		err = Ftruncate(h, 0)
   423  		if err != nil {
   424  			CloseHandle(h)
   425  			return InvalidHandle, err
   426  		}
   427  	}
   428  	return h, nil
   429  }
   430  
   431  func Read(fd Handle, p []byte) (n int, err error) {
   432  	var done uint32
   433  	e := ReadFile(fd, p, &done, nil)
   434  	if e != nil {
   435  		if e == ERROR_BROKEN_PIPE {
   436  			// NOTE(brainman): work around ERROR_BROKEN_PIPE is returned on reading EOF from stdin
   437  			return 0, nil
   438  		}
   439  		return 0, e
   440  	}
   441  	return int(done), nil
   442  }
   443  
   444  func Write(fd Handle, p []byte) (n int, err error) {
   445  	var done uint32
   446  	e := WriteFile(fd, p, &done, nil)
   447  	if e != nil {
   448  		return 0, e
   449  	}
   450  	return int(done), nil
   451  }
   452  
   453  func ReadFile(fd Handle, p []byte, done *uint32, overlapped *Overlapped) error {
   454  	err := readFile(fd, p, done, overlapped)
   455  	if race.Enabled {
   456  		if *done > 0 {
   457  			race.WriteRange(unsafe.Pointer(&p[0]), int(*done))
   458  		}
   459  		race.Acquire(unsafe.Pointer(&ioSync))
   460  	}
   461  	if msan.Enabled && *done > 0 {
   462  		msan.Write(unsafe.Pointer(&p[0]), uintptr(*done))
   463  	}
   464  	if asan.Enabled && *done > 0 {
   465  		asan.Write(unsafe.Pointer(&p[0]), uintptr(*done))
   466  	}
   467  	return err
   468  }
   469  
   470  func WriteFile(fd Handle, p []byte, done *uint32, overlapped *Overlapped) error {
   471  	if race.Enabled {
   472  		race.ReleaseMerge(unsafe.Pointer(&ioSync))
   473  	}
   474  	err := writeFile(fd, p, done, overlapped)
   475  	if race.Enabled && *done > 0 {
   476  		race.ReadRange(unsafe.Pointer(&p[0]), int(*done))
   477  	}
   478  	if msan.Enabled && *done > 0 {
   479  		msan.Read(unsafe.Pointer(&p[0]), uintptr(*done))
   480  	}
   481  	if asan.Enabled && *done > 0 {
   482  		asan.Read(unsafe.Pointer(&p[0]), uintptr(*done))
   483  	}
   484  	return err
   485  }
   486  
   487  var ioSync int64
   488  
   489  var procSetFilePointerEx = modkernel32.NewProc("SetFilePointerEx")
   490  
   491  const ptrSize = unsafe.Sizeof(uintptr(0))
   492  
   493  // setFilePointerEx calls SetFilePointerEx.
   494  // See https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-setfilepointerex
   495  func setFilePointerEx(handle Handle, distToMove int64, newFilePointer *int64, whence uint32) error {
   496  	var e1 Errno
   497  	if unsafe.Sizeof(uintptr(0)) == 8 {
   498  		_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 4, uintptr(handle), uintptr(distToMove), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence), 0, 0)
   499  	} else {
   500  		// Different 32-bit systems disgaree about whether distToMove starts 8-byte aligned.
   501  		switch runtime.GOARCH {
   502  		default:
   503  			panic("unsupported 32-bit architecture")
   504  		case "386":
   505  			// distToMove is a LARGE_INTEGER, which is 64 bits.
   506  			_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 5, uintptr(handle), uintptr(distToMove), uintptr(distToMove>>32), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence), 0)
   507  		case "arm":
   508  			// distToMove must be 8-byte aligned per ARM calling convention
   509  			// https://docs.microsoft.com/en-us/cpp/build/overview-of-arm-abi-conventions#stage-c-assignment-of-arguments-to-registers-and-stack
   510  			_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 6, uintptr(handle), 0, uintptr(distToMove), uintptr(distToMove>>32), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence))
   511  		}
   512  	}
   513  	if e1 != 0 {
   514  		return errnoErr(e1)
   515  	}
   516  	return nil
   517  }
   518  
   519  func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) {
   520  	var w uint32
   521  	switch whence {
   522  	case 0:
   523  		w = FILE_BEGIN
   524  	case 1:
   525  		w = FILE_CURRENT
   526  	case 2:
   527  		w = FILE_END
   528  	}
   529  	err = setFilePointerEx(fd, offset, &newoffset, w)
   530  	return
   531  }
   532  
   533  func Close(fd Handle) (err error) {
   534  	return CloseHandle(fd)
   535  }
   536  
   537  var (
   538  	Stdin  = getStdHandle(STD_INPUT_HANDLE)
   539  	Stdout = getStdHandle(STD_OUTPUT_HANDLE)
   540  	Stderr = getStdHandle(STD_ERROR_HANDLE)
   541  )
   542  
   543  func getStdHandle(h int) (fd Handle) {
   544  	r, _ := GetStdHandle(h)
   545  	return r
   546  }
   547  
   548  const ImplementsGetwd = true
   549  
   550  func Getwd() (wd string, err error) {
   551  	b := make([]uint16, 300)
   552  	// The path of the current directory may not fit in the initial 300-word
   553  	// buffer when long path support is enabled. The current directory may also
   554  	// change between subsequent calls of GetCurrentDirectory. As a result, we
   555  	// need to retry the call in a loop until the current directory fits, each
   556  	// time with a bigger buffer.
   557  	for {
   558  		n, e := GetCurrentDirectory(uint32(len(b)), &b[0])
   559  		if e != nil {
   560  			return "", e
   561  		}
   562  		if int(n) <= len(b) {
   563  			return UTF16ToString(b[:n]), nil
   564  		}
   565  		b = make([]uint16, n)
   566  	}
   567  }
   568  
   569  func Chdir(path string) (err error) {
   570  	pathp, err := UTF16PtrFromString(path)
   571  	if err != nil {
   572  		return err
   573  	}
   574  	return SetCurrentDirectory(pathp)
   575  }
   576  
   577  func Mkdir(path string, mode uint32) (err error) {
   578  	pathp, err := UTF16PtrFromString(path)
   579  	if err != nil {
   580  		return err
   581  	}
   582  	return CreateDirectory(pathp, nil)
   583  }
   584  
   585  func Rmdir(path string) (err error) {
   586  	pathp, err := UTF16PtrFromString(path)
   587  	if err != nil {
   588  		return err
   589  	}
   590  	return RemoveDirectory(pathp)
   591  }
   592  
   593  func Unlink(path string) (err error) {
   594  	pathp, err := UTF16PtrFromString(path)
   595  	if err != nil {
   596  		return err
   597  	}
   598  	return DeleteFile(pathp)
   599  }
   600  
   601  func Rename(oldpath, newpath string) (err error) {
   602  	from, err := UTF16PtrFromString(oldpath)
   603  	if err != nil {
   604  		return err
   605  	}
   606  	to, err := UTF16PtrFromString(newpath)
   607  	if err != nil {
   608  		return err
   609  	}
   610  	return MoveFile(from, to)
   611  }
   612  
   613  func ComputerName() (name string, err error) {
   614  	var n uint32 = MAX_COMPUTERNAME_LENGTH + 1
   615  	b := make([]uint16, n)
   616  	e := GetComputerName(&b[0], &n)
   617  	if e != nil {
   618  		return "", e
   619  	}
   620  	return UTF16ToString(b[:n]), nil
   621  }
   622  
   623  func Ftruncate(fd Handle, length int64) (err error) {
   624  	type _FILE_END_OF_FILE_INFO struct {
   625  		EndOfFile int64
   626  	}
   627  	const FileEndOfFileInfo = 6
   628  	var info _FILE_END_OF_FILE_INFO
   629  	info.EndOfFile = length
   630  	return setFileInformationByHandle(fd, FileEndOfFileInfo, unsafe.Pointer(&info), uint32(unsafe.Sizeof(info)))
   631  }
   632  
   633  func Gettimeofday(tv *Timeval) (err error) {
   634  	var ft Filetime
   635  	GetSystemTimeAsFileTime(&ft)
   636  	*tv = NsecToTimeval(ft.Nanoseconds())
   637  	return nil
   638  }
   639  
   640  func Pipe(p []Handle) (err error) {
   641  	if len(p) != 2 {
   642  		return EINVAL
   643  	}
   644  	var r, w Handle
   645  	e := CreatePipe(&r, &w, makeInheritSa(), 0)
   646  	if e != nil {
   647  		return e
   648  	}
   649  	p[0] = r
   650  	p[1] = w
   651  	return nil
   652  }
   653  
   654  func Utimes(path string, tv []Timeval) (err error) {
   655  	if len(tv) != 2 {
   656  		return EINVAL
   657  	}
   658  	pathp, e := UTF16PtrFromString(path)
   659  	if e != nil {
   660  		return e
   661  	}
   662  	h, e := CreateFile(pathp,
   663  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   664  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   665  	if e != nil {
   666  		return e
   667  	}
   668  	defer Close(h)
   669  	a := Filetime{}
   670  	w := Filetime{}
   671  	if tv[0].Nanoseconds() != 0 {
   672  		a = NsecToFiletime(tv[0].Nanoseconds())
   673  	}
   674  	if tv[0].Nanoseconds() != 0 {
   675  		w = NsecToFiletime(tv[1].Nanoseconds())
   676  	}
   677  	return SetFileTime(h, nil, &a, &w)
   678  }
   679  
   680  // This matches the value in os/file_windows.go.
   681  const _UTIME_OMIT = -1
   682  
   683  func UtimesNano(path string, ts []Timespec) (err error) {
   684  	if len(ts) != 2 {
   685  		return EINVAL
   686  	}
   687  	pathp, e := UTF16PtrFromString(path)
   688  	if e != nil {
   689  		return e
   690  	}
   691  	h, e := CreateFile(pathp,
   692  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   693  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   694  	if e != nil {
   695  		return e
   696  	}
   697  	defer Close(h)
   698  	a := Filetime{}
   699  	w := Filetime{}
   700  	if ts[0].Nsec != _UTIME_OMIT {
   701  		a = NsecToFiletime(TimespecToNsec(ts[0]))
   702  	}
   703  	if ts[1].Nsec != _UTIME_OMIT {
   704  		w = NsecToFiletime(TimespecToNsec(ts[1]))
   705  	}
   706  	return SetFileTime(h, nil, &a, &w)
   707  }
   708  
   709  func Fsync(fd Handle) (err error) {
   710  	return FlushFileBuffers(fd)
   711  }
   712  
   713  func Chmod(path string, mode uint32) (err error) {
   714  	p, e := UTF16PtrFromString(path)
   715  	if e != nil {
   716  		return e
   717  	}
   718  	attrs, e := GetFileAttributes(p)
   719  	if e != nil {
   720  		return e
   721  	}
   722  	if mode&S_IWRITE != 0 {
   723  		attrs &^= FILE_ATTRIBUTE_READONLY
   724  	} else {
   725  		attrs |= FILE_ATTRIBUTE_READONLY
   726  	}
   727  	return SetFileAttributes(p, attrs)
   728  }
   729  
   730  func LoadCancelIoEx() error {
   731  	return procCancelIoEx.Find()
   732  }
   733  
   734  func LoadSetFileCompletionNotificationModes() error {
   735  	return procSetFileCompletionNotificationModes.Find()
   736  }
   737  
   738  // net api calls
   739  
   740  const socket_error = uintptr(^uint32(0))
   741  
   742  //sys	WSAStartup(verreq uint32, data *WSAData) (sockerr error) = ws2_32.WSAStartup
   743  //sys	WSACleanup() (err error) [failretval==socket_error] = ws2_32.WSACleanup
   744  //sys	WSAIoctl(s Handle, iocc uint32, inbuf *byte, cbif uint32, outbuf *byte, cbob uint32, cbbr *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) [failretval==socket_error] = ws2_32.WSAIoctl
   745  //sys	socket(af int32, typ int32, protocol int32) (handle Handle, err error) [failretval==InvalidHandle] = ws2_32.socket
   746  //sys	Setsockopt(s Handle, level int32, optname int32, optval *byte, optlen int32) (err error) [failretval==socket_error] = ws2_32.setsockopt
   747  //sys	Getsockopt(s Handle, level int32, optname int32, optval *byte, optlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockopt
   748  //sys	bind(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.bind
   749  //sys	connect(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.connect
   750  //sys	getsockname(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockname
   751  //sys	getpeername(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getpeername
   752  //sys	listen(s Handle, backlog int32) (err error) [failretval==socket_error] = ws2_32.listen
   753  //sys	shutdown(s Handle, how int32) (err error) [failretval==socket_error] = ws2_32.shutdown
   754  //sys	Closesocket(s Handle) (err error) [failretval==socket_error] = ws2_32.closesocket
   755  //sys	AcceptEx(ls Handle, as Handle, buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, recvd *uint32, overlapped *Overlapped) (err error) = mswsock.AcceptEx
   756  //sys	GetAcceptExSockaddrs(buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, lrsa **RawSockaddrAny, lrsalen *int32, rrsa **RawSockaddrAny, rrsalen *int32) = mswsock.GetAcceptExSockaddrs
   757  //sys	WSARecv(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecv
   758  //sys	WSASend(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASend
   759  //sys	WSARecvFrom(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32,  from *RawSockaddrAny, fromlen *int32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecvFrom
   760  //sys	WSASendTo(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *RawSockaddrAny, tolen int32,  overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASendTo
   761  //sys	GetHostByName(name string) (h *Hostent, err error) [failretval==nil] = ws2_32.gethostbyname
   762  //sys	GetServByName(name string, proto string) (s *Servent, err error) [failretval==nil] = ws2_32.getservbyname
   763  //sys	Ntohs(netshort uint16) (u uint16) = ws2_32.ntohs
   764  //sys	GetProtoByName(name string) (p *Protoent, err error) [failretval==nil] = ws2_32.getprotobyname
   765  //sys	DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status error) = dnsapi.DnsQuery_W
   766  //sys	DnsRecordListFree(rl *DNSRecord, freetype uint32) = dnsapi.DnsRecordListFree
   767  //sys	DnsNameCompare(name1 *uint16, name2 *uint16) (same bool) = dnsapi.DnsNameCompare_W
   768  //sys	GetAddrInfoW(nodename *uint16, servicename *uint16, hints *AddrinfoW, result **AddrinfoW) (sockerr error) = ws2_32.GetAddrInfoW
   769  //sys	FreeAddrInfoW(addrinfo *AddrinfoW) = ws2_32.FreeAddrInfoW
   770  //sys	GetIfEntry(pIfRow *MibIfRow) (errcode error) = iphlpapi.GetIfEntry
   771  //sys	GetAdaptersInfo(ai *IpAdapterInfo, ol *uint32) (errcode error) = iphlpapi.GetAdaptersInfo
   772  //sys	SetFileCompletionNotificationModes(handle Handle, flags uint8) (err error) = kernel32.SetFileCompletionNotificationModes
   773  //sys	WSAEnumProtocols(protocols *int32, protocolBuffer *WSAProtocolInfo, bufferLength *uint32) (n int32, err error) [failretval==-1] = ws2_32.WSAEnumProtocolsW
   774  
   775  // For testing: clients can set this flag to force
   776  // creation of IPv6 sockets to return [EAFNOSUPPORT].
   777  var SocketDisableIPv6 bool
   778  
   779  type RawSockaddrInet4 struct {
   780  	Family uint16
   781  	Port   uint16
   782  	Addr   [4]byte /* in_addr */
   783  	Zero   [8]uint8
   784  }
   785  
   786  type RawSockaddrInet6 struct {
   787  	Family   uint16
   788  	Port     uint16
   789  	Flowinfo uint32
   790  	Addr     [16]byte /* in6_addr */
   791  	Scope_id uint32
   792  }
   793  
   794  type RawSockaddr struct {
   795  	Family uint16
   796  	Data   [14]int8
   797  }
   798  
   799  type RawSockaddrAny struct {
   800  	Addr RawSockaddr
   801  	Pad  [100]int8
   802  }
   803  
   804  type Sockaddr interface {
   805  	sockaddr() (ptr unsafe.Pointer, len int32, err error) // lowercase; only we can define Sockaddrs
   806  }
   807  
   808  type SockaddrInet4 struct {
   809  	Port int
   810  	Addr [4]byte
   811  	raw  RawSockaddrInet4
   812  }
   813  
   814  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, int32, error) {
   815  	if sa.Port < 0 || sa.Port > 0xFFFF {
   816  		return nil, 0, EINVAL
   817  	}
   818  	sa.raw.Family = AF_INET
   819  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   820  	p[0] = byte(sa.Port >> 8)
   821  	p[1] = byte(sa.Port)
   822  	sa.raw.Addr = sa.Addr
   823  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   824  }
   825  
   826  type SockaddrInet6 struct {
   827  	Port   int
   828  	ZoneId uint32
   829  	Addr   [16]byte
   830  	raw    RawSockaddrInet6
   831  }
   832  
   833  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, int32, error) {
   834  	if sa.Port < 0 || sa.Port > 0xFFFF {
   835  		return nil, 0, EINVAL
   836  	}
   837  	sa.raw.Family = AF_INET6
   838  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   839  	p[0] = byte(sa.Port >> 8)
   840  	p[1] = byte(sa.Port)
   841  	sa.raw.Scope_id = sa.ZoneId
   842  	sa.raw.Addr = sa.Addr
   843  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   844  }
   845  
   846  type RawSockaddrUnix struct {
   847  	Family uint16
   848  	Path   [UNIX_PATH_MAX]int8
   849  }
   850  
   851  type SockaddrUnix struct {
   852  	Name string
   853  	raw  RawSockaddrUnix
   854  }
   855  
   856  func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, int32, error) {
   857  	name := sa.Name
   858  	n := len(name)
   859  	if n > len(sa.raw.Path) {
   860  		return nil, 0, EINVAL
   861  	}
   862  	// Abstract addresses start with NUL.
   863  	// '@' is also a valid way to specify abstract addresses.
   864  	isAbstract := n > 0 && (name[0] == '@' || name[0] == '\x00')
   865  
   866  	// Non-abstract named addresses are NUL terminated.
   867  	// The length can't use the full capacity as we need to add NUL.
   868  	if n == len(sa.raw.Path) && !isAbstract {
   869  		return nil, 0, EINVAL
   870  	}
   871  	sa.raw.Family = AF_UNIX
   872  	for i := 0; i < n; i++ {
   873  		sa.raw.Path[i] = int8(name[i])
   874  	}
   875  	// Length is family + name (+ NUL if non-abstract).
   876  	// Family is of type uint16 (2 bytes).
   877  	sl := int32(2 + n)
   878  	if isAbstract {
   879  		// Abstract addresses are not NUL terminated.
   880  		// We rewrite '@' prefix to NUL here.
   881  		sa.raw.Path[0] = 0
   882  	} else if n > 0 {
   883  		// Add NUL for non-abstract named addresses.
   884  		sl++
   885  	}
   886  
   887  	return unsafe.Pointer(&sa.raw), sl, nil
   888  }
   889  
   890  func (rsa *RawSockaddrAny) Sockaddr() (Sockaddr, error) {
   891  	switch rsa.Addr.Family {
   892  	case AF_UNIX:
   893  		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
   894  		sa := new(SockaddrUnix)
   895  		if pp.Path[0] == 0 {
   896  			// "Abstract" Unix domain socket.
   897  			// Rewrite leading NUL as @ for textual display.
   898  			// (This is the standard convention.)
   899  			// Not friendly to overwrite in place,
   900  			// but the callers below don't care.
   901  			pp.Path[0] = '@'
   902  		}
   903  
   904  		// Assume path ends at NUL.
   905  		// This is not technically the Linux semantics for
   906  		// abstract Unix domain sockets--they are supposed
   907  		// to be uninterpreted fixed-size binary blobs--but
   908  		// everyone uses this convention.
   909  		n := 0
   910  		for n < len(pp.Path) && pp.Path[n] != 0 {
   911  			n++
   912  		}
   913  		sa.Name = string(unsafe.Slice((*byte)(unsafe.Pointer(&pp.Path[0])), n))
   914  		return sa, nil
   915  
   916  	case AF_INET:
   917  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
   918  		sa := new(SockaddrInet4)
   919  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   920  		sa.Port = int(p[0])<<8 + int(p[1])
   921  		sa.Addr = pp.Addr
   922  		return sa, nil
   923  
   924  	case AF_INET6:
   925  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
   926  		sa := new(SockaddrInet6)
   927  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   928  		sa.Port = int(p[0])<<8 + int(p[1])
   929  		sa.ZoneId = pp.Scope_id
   930  		sa.Addr = pp.Addr
   931  		return sa, nil
   932  	}
   933  	return nil, EAFNOSUPPORT
   934  }
   935  
   936  func Socket(domain, typ, proto int) (fd Handle, err error) {
   937  	if domain == AF_INET6 && SocketDisableIPv6 {
   938  		return InvalidHandle, EAFNOSUPPORT
   939  	}
   940  	return socket(int32(domain), int32(typ), int32(proto))
   941  }
   942  
   943  func SetsockoptInt(fd Handle, level, opt int, value int) (err error) {
   944  	v := int32(value)
   945  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&v)), int32(unsafe.Sizeof(v)))
   946  }
   947  
   948  func Bind(fd Handle, sa Sockaddr) (err error) {
   949  	ptr, n, err := sa.sockaddr()
   950  	if err != nil {
   951  		return err
   952  	}
   953  	return bind(fd, ptr, n)
   954  }
   955  
   956  func Connect(fd Handle, sa Sockaddr) (err error) {
   957  	ptr, n, err := sa.sockaddr()
   958  	if err != nil {
   959  		return err
   960  	}
   961  	return connect(fd, ptr, n)
   962  }
   963  
   964  func Getsockname(fd Handle) (sa Sockaddr, err error) {
   965  	var rsa RawSockaddrAny
   966  	l := int32(unsafe.Sizeof(rsa))
   967  	if err = getsockname(fd, &rsa, &l); err != nil {
   968  		return
   969  	}
   970  	return rsa.Sockaddr()
   971  }
   972  
   973  func Getpeername(fd Handle) (sa Sockaddr, err error) {
   974  	var rsa RawSockaddrAny
   975  	l := int32(unsafe.Sizeof(rsa))
   976  	if err = getpeername(fd, &rsa, &l); err != nil {
   977  		return
   978  	}
   979  	return rsa.Sockaddr()
   980  }
   981  
   982  func Listen(s Handle, n int) (err error) {
   983  	return listen(s, int32(n))
   984  }
   985  
   986  func Shutdown(fd Handle, how int) (err error) {
   987  	return shutdown(fd, int32(how))
   988  }
   989  
   990  func WSASendto(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to Sockaddr, overlapped *Overlapped, croutine *byte) (err error) {
   991  	var rsa unsafe.Pointer
   992  	var len int32
   993  	if to != nil {
   994  		rsa, len, err = to.sockaddr()
   995  		if err != nil {
   996  			return err
   997  		}
   998  	}
   999  	r1, _, e1 := Syscall9(procWSASendTo.Addr(), 9, uintptr(s), uintptr(unsafe.Pointer(bufs)), uintptr(bufcnt), uintptr(unsafe.Pointer(sent)), uintptr(flags), uintptr(unsafe.Pointer(rsa)), uintptr(len), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)))
  1000  	if r1 == socket_error {
  1001  		if e1 != 0 {
  1002  			err = errnoErr(e1)
  1003  		} else {
  1004  			err = EINVAL
  1005  		}
  1006  	}
  1007  	return err
  1008  }
  1009  
  1010  func wsaSendtoInet4(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *SockaddrInet4, overlapped *Overlapped, croutine *byte) (err error) {
  1011  	rsa, len, err := to.sockaddr()
  1012  	if err != nil {
  1013  		return err
  1014  	}
  1015  	r1, _, e1 := Syscall9(procWSASendTo.Addr(), 9, uintptr(s), uintptr(unsafe.Pointer(bufs)), uintptr(bufcnt), uintptr(unsafe.Pointer(sent)), uintptr(flags), uintptr(unsafe.Pointer(rsa)), uintptr(len), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)))
  1016  	if r1 == socket_error {
  1017  		if e1 != 0 {
  1018  			err = errnoErr(e1)
  1019  		} else {
  1020  			err = EINVAL
  1021  		}
  1022  	}
  1023  	return err
  1024  }
  1025  
  1026  func wsaSendtoInet6(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *SockaddrInet6, overlapped *Overlapped, croutine *byte) (err error) {
  1027  	rsa, len, err := to.sockaddr()
  1028  	if err != nil {
  1029  		return err
  1030  	}
  1031  	r1, _, e1 := Syscall9(procWSASendTo.Addr(), 9, uintptr(s), uintptr(unsafe.Pointer(bufs)), uintptr(bufcnt), uintptr(unsafe.Pointer(sent)), uintptr(flags), uintptr(unsafe.Pointer(rsa)), uintptr(len), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)))
  1032  	if r1 == socket_error {
  1033  		if e1 != 0 {
  1034  			err = errnoErr(e1)
  1035  		} else {
  1036  			err = EINVAL
  1037  		}
  1038  	}
  1039  	return err
  1040  }
  1041  
  1042  func LoadGetAddrInfo() error {
  1043  	return procGetAddrInfoW.Find()
  1044  }
  1045  
  1046  var connectExFunc struct {
  1047  	once sync.Once
  1048  	addr uintptr
  1049  	err  error
  1050  }
  1051  
  1052  func LoadConnectEx() error {
  1053  	connectExFunc.once.Do(func() {
  1054  		var s Handle
  1055  		s, connectExFunc.err = Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)
  1056  		if connectExFunc.err != nil {
  1057  			return
  1058  		}
  1059  		defer CloseHandle(s)
  1060  		var n uint32
  1061  		connectExFunc.err = WSAIoctl(s,
  1062  			SIO_GET_EXTENSION_FUNCTION_POINTER,
  1063  			(*byte)(unsafe.Pointer(&WSAID_CONNECTEX)),
  1064  			uint32(unsafe.Sizeof(WSAID_CONNECTEX)),
  1065  			(*byte)(unsafe.Pointer(&connectExFunc.addr)),
  1066  			uint32(unsafe.Sizeof(connectExFunc.addr)),
  1067  			&n, nil, 0)
  1068  	})
  1069  	return connectExFunc.err
  1070  }
  1071  
  1072  func connectEx(s Handle, name unsafe.Pointer, namelen int32, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) (err error) {
  1073  	r1, _, e1 := Syscall9(connectExFunc.addr, 7, uintptr(s), uintptr(name), uintptr(namelen), uintptr(unsafe.Pointer(sendBuf)), uintptr(sendDataLen), uintptr(unsafe.Pointer(bytesSent)), uintptr(unsafe.Pointer(overlapped)), 0, 0)
  1074  	if r1 == 0 {
  1075  		if e1 != 0 {
  1076  			err = error(e1)
  1077  		} else {
  1078  			err = EINVAL
  1079  		}
  1080  	}
  1081  	return
  1082  }
  1083  
  1084  func ConnectEx(fd Handle, sa Sockaddr, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) error {
  1085  	err := LoadConnectEx()
  1086  	if err != nil {
  1087  		return errorspkg.New("failed to find ConnectEx: " + err.Error())
  1088  	}
  1089  	ptr, n, err := sa.sockaddr()
  1090  	if err != nil {
  1091  		return err
  1092  	}
  1093  	return connectEx(fd, ptr, n, sendBuf, sendDataLen, bytesSent, overlapped)
  1094  }
  1095  
  1096  // Invented structures to support what package os expects.
  1097  type Rusage struct {
  1098  	CreationTime Filetime
  1099  	ExitTime     Filetime
  1100  	KernelTime   Filetime
  1101  	UserTime     Filetime
  1102  }
  1103  
  1104  type WaitStatus struct {
  1105  	ExitCode uint32
  1106  }
  1107  
  1108  func (w WaitStatus) Exited() bool { return true }
  1109  
  1110  func (w WaitStatus) ExitStatus() int { return int(w.ExitCode) }
  1111  
  1112  func (w WaitStatus) Signal() Signal { return -1 }
  1113  
  1114  func (w WaitStatus) CoreDump() bool { return false }
  1115  
  1116  func (w WaitStatus) Stopped() bool { return false }
  1117  
  1118  func (w WaitStatus) Continued() bool { return false }
  1119  
  1120  func (w WaitStatus) StopSignal() Signal { return -1 }
  1121  
  1122  func (w WaitStatus) Signaled() bool { return false }
  1123  
  1124  func (w WaitStatus) TrapCause() int { return -1 }
  1125  
  1126  // Timespec is an invented structure on Windows, but here for
  1127  // consistency with the syscall package for other operating systems.
  1128  type Timespec struct {
  1129  	Sec  int64
  1130  	Nsec int64
  1131  }
  1132  
  1133  func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
  1134  
  1135  func NsecToTimespec(nsec int64) (ts Timespec) {
  1136  	ts.Sec = nsec / 1e9
  1137  	ts.Nsec = nsec % 1e9
  1138  	return
  1139  }
  1140  
  1141  // TODO(brainman): fix all needed for net
  1142  
  1143  func Accept(fd Handle) (nfd Handle, sa Sockaddr, err error) { return 0, nil, EWINDOWS }
  1144  func Recvfrom(fd Handle, p []byte, flags int) (n int, from Sockaddr, err error) {
  1145  	return 0, nil, EWINDOWS
  1146  }
  1147  func Sendto(fd Handle, p []byte, flags int, to Sockaddr) (err error)       { return EWINDOWS }
  1148  func SetsockoptTimeval(fd Handle, level, opt int, tv *Timeval) (err error) { return EWINDOWS }
  1149  
  1150  // The Linger struct is wrong but we only noticed after Go 1.
  1151  // sysLinger is the real system call structure.
  1152  
  1153  // BUG(brainman): The definition of Linger is not appropriate for direct use
  1154  // with Setsockopt and Getsockopt.
  1155  // Use SetsockoptLinger instead.
  1156  
  1157  type Linger struct {
  1158  	Onoff  int32
  1159  	Linger int32
  1160  }
  1161  
  1162  type sysLinger struct {
  1163  	Onoff  uint16
  1164  	Linger uint16
  1165  }
  1166  
  1167  type IPMreq struct {
  1168  	Multiaddr [4]byte /* in_addr */
  1169  	Interface [4]byte /* in_addr */
  1170  }
  1171  
  1172  type IPv6Mreq struct {
  1173  	Multiaddr [16]byte /* in6_addr */
  1174  	Interface uint32
  1175  }
  1176  
  1177  func GetsockoptInt(fd Handle, level, opt int) (int, error) {
  1178  	optval := int32(0)
  1179  	optlen := int32(unsafe.Sizeof(optval))
  1180  	err := Getsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&optval)), &optlen)
  1181  	return int(optval), err
  1182  }
  1183  
  1184  func SetsockoptLinger(fd Handle, level, opt int, l *Linger) (err error) {
  1185  	sys := sysLinger{Onoff: uint16(l.Onoff), Linger: uint16(l.Linger)}
  1186  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&sys)), int32(unsafe.Sizeof(sys)))
  1187  }
  1188  
  1189  func SetsockoptInet4Addr(fd Handle, level, opt int, value [4]byte) (err error) {
  1190  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&value[0])), 4)
  1191  }
  1192  func SetsockoptIPMreq(fd Handle, level, opt int, mreq *IPMreq) (err error) {
  1193  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(mreq)), int32(unsafe.Sizeof(*mreq)))
  1194  }
  1195  func SetsockoptIPv6Mreq(fd Handle, level, opt int, mreq *IPv6Mreq) (err error) { return EWINDOWS }
  1196  
  1197  func Getpid() (pid int) { return int(getCurrentProcessId()) }
  1198  
  1199  func FindFirstFile(name *uint16, data *Win32finddata) (handle Handle, err error) {
  1200  	// NOTE(rsc): The Win32finddata struct is wrong for the system call:
  1201  	// the two paths are each one uint16 short. Use the correct struct,
  1202  	// a win32finddata1, and then copy the results out.
  1203  	// There is no loss of expressivity here, because the final
  1204  	// uint16, if it is used, is supposed to be a NUL, and Go doesn't need that.
  1205  	// For Go 1.1, we might avoid the allocation of win32finddata1 here
  1206  	// by adding a final Bug [2]uint16 field to the struct and then
  1207  	// adjusting the fields in the result directly.
  1208  	var data1 win32finddata1
  1209  	handle, err = findFirstFile1(name, &data1)
  1210  	if err == nil {
  1211  		copyFindData(data, &data1)
  1212  	}
  1213  	return
  1214  }
  1215  
  1216  func FindNextFile(handle Handle, data *Win32finddata) (err error) {
  1217  	var data1 win32finddata1
  1218  	err = findNextFile1(handle, &data1)
  1219  	if err == nil {
  1220  		copyFindData(data, &data1)
  1221  	}
  1222  	return
  1223  }
  1224  
  1225  func getProcessEntry(pid int) (*ProcessEntry32, error) {
  1226  	snapshot, err := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
  1227  	if err != nil {
  1228  		return nil, err
  1229  	}
  1230  	defer CloseHandle(snapshot)
  1231  	var procEntry ProcessEntry32
  1232  	procEntry.Size = uint32(unsafe.Sizeof(procEntry))
  1233  	if err = Process32First(snapshot, &procEntry); err != nil {
  1234  		return nil, err
  1235  	}
  1236  	for {
  1237  		if procEntry.ProcessID == uint32(pid) {
  1238  			return &procEntry, nil
  1239  		}
  1240  		err = Process32Next(snapshot, &procEntry)
  1241  		if err != nil {
  1242  			return nil, err
  1243  		}
  1244  	}
  1245  }
  1246  
  1247  func Getppid() (ppid int) {
  1248  	pe, err := getProcessEntry(Getpid())
  1249  	if err != nil {
  1250  		return -1
  1251  	}
  1252  	return int(pe.ParentProcessID)
  1253  }
  1254  
  1255  func fdpath(fd Handle, buf []uint16) ([]uint16, error) {
  1256  	const (
  1257  		FILE_NAME_NORMALIZED = 0
  1258  		VOLUME_NAME_DOS      = 0
  1259  	)
  1260  	for {
  1261  		n, err := getFinalPathNameByHandle(fd, &buf[0], uint32(len(buf)), FILE_NAME_NORMALIZED|VOLUME_NAME_DOS)
  1262  		if err == nil {
  1263  			buf = buf[:n]
  1264  			break
  1265  		}
  1266  		if err != _ERROR_NOT_ENOUGH_MEMORY {
  1267  			return nil, err
  1268  		}
  1269  		buf = append(buf, make([]uint16, n-uint32(len(buf)))...)
  1270  	}
  1271  	return buf, nil
  1272  }
  1273  
  1274  func Fchdir(fd Handle) (err error) {
  1275  	var buf [MAX_PATH + 1]uint16
  1276  	path, err := fdpath(fd, buf[:])
  1277  	if err != nil {
  1278  		return err
  1279  	}
  1280  	// When using VOLUME_NAME_DOS, the path is always prefixed by "\\?\".
  1281  	// That prefix tells the Windows APIs to disable all string parsing and to send
  1282  	// the string that follows it straight to the file system.
  1283  	// Although SetCurrentDirectory and GetCurrentDirectory do support the "\\?\" prefix,
  1284  	// some other Windows APIs don't. If the prefix is not removed here, it will leak
  1285  	// to Getwd, and we don't want such a general-purpose function to always return a
  1286  	// path with the "\\?\" prefix after Fchdir is called.
  1287  	// The downside is that APIs that do support it will parse the path and try to normalize it,
  1288  	// when it's already normalized.
  1289  	if len(path) >= 4 && path[0] == '\\' && path[1] == '\\' && path[2] == '?' && path[3] == '\\' {
  1290  		path = path[4:]
  1291  	}
  1292  	return SetCurrentDirectory(&path[0])
  1293  }
  1294  
  1295  // TODO(brainman): fix all needed for os
  1296  func Link(oldpath, newpath string) (err error) { return EWINDOWS }
  1297  func Symlink(path, link string) (err error)    { return EWINDOWS }
  1298  
  1299  func Fchmod(fd Handle, mode uint32) (err error)        { return EWINDOWS }
  1300  func Chown(path string, uid int, gid int) (err error)  { return EWINDOWS }
  1301  func Lchown(path string, uid int, gid int) (err error) { return EWINDOWS }
  1302  func Fchown(fd Handle, uid int, gid int) (err error)   { return EWINDOWS }
  1303  
  1304  func Getuid() (uid int)                  { return -1 }
  1305  func Geteuid() (euid int)                { return -1 }
  1306  func Getgid() (gid int)                  { return -1 }
  1307  func Getegid() (egid int)                { return -1 }
  1308  func Getgroups() (gids []int, err error) { return nil, EWINDOWS }
  1309  
  1310  type Signal int
  1311  
  1312  func (s Signal) Signal() {}
  1313  
  1314  func (s Signal) String() string {
  1315  	if 0 <= s && int(s) < len(signals) {
  1316  		str := signals[s]
  1317  		if str != "" {
  1318  			return str
  1319  		}
  1320  	}
  1321  	return "signal " + itoa.Itoa(int(s))
  1322  }
  1323  
  1324  func LoadCreateSymbolicLink() error {
  1325  	return procCreateSymbolicLinkW.Find()
  1326  }
  1327  
  1328  // Readlink returns the destination of the named symbolic link.
  1329  func Readlink(path string, buf []byte) (n int, err error) {
  1330  	fd, err := CreateFile(StringToUTF16Ptr(path), GENERIC_READ, 0, nil, OPEN_EXISTING,
  1331  		FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, 0)
  1332  	if err != nil {
  1333  		return -1, err
  1334  	}
  1335  	defer CloseHandle(fd)
  1336  
  1337  	rdbbuf := make([]byte, MAXIMUM_REPARSE_DATA_BUFFER_SIZE)
  1338  	var bytesReturned uint32
  1339  	err = DeviceIoControl(fd, FSCTL_GET_REPARSE_POINT, nil, 0, &rdbbuf[0], uint32(len(rdbbuf)), &bytesReturned, nil)
  1340  	if err != nil {
  1341  		return -1, err
  1342  	}
  1343  
  1344  	rdb := (*reparseDataBuffer)(unsafe.Pointer(&rdbbuf[0]))
  1345  	var s string
  1346  	switch rdb.ReparseTag {
  1347  	case IO_REPARSE_TAG_SYMLINK:
  1348  		data := (*symbolicLinkReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1349  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1350  		s = UTF16ToString(p[data.SubstituteNameOffset/2 : (data.SubstituteNameOffset+data.SubstituteNameLength)/2])
  1351  		if data.Flags&_SYMLINK_FLAG_RELATIVE == 0 {
  1352  			if len(s) >= 4 && s[:4] == `\??\` {
  1353  				s = s[4:]
  1354  				switch {
  1355  				case len(s) >= 2 && s[1] == ':': // \??\C:\foo\bar
  1356  					// do nothing
  1357  				case len(s) >= 4 && s[:4] == `UNC\`: // \??\UNC\foo\bar
  1358  					s = `\\` + s[4:]
  1359  				default:
  1360  					// unexpected; do nothing
  1361  				}
  1362  			} else {
  1363  				// unexpected; do nothing
  1364  			}
  1365  		}
  1366  	case _IO_REPARSE_TAG_MOUNT_POINT:
  1367  		data := (*mountPointReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1368  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1369  		s = UTF16ToString(p[data.SubstituteNameOffset/2 : (data.SubstituteNameOffset+data.SubstituteNameLength)/2])
  1370  		if len(s) >= 4 && s[:4] == `\??\` { // \??\C:\foo\bar
  1371  			s = s[4:]
  1372  		} else {
  1373  			// unexpected; do nothing
  1374  		}
  1375  	default:
  1376  		// the path is not a symlink or junction but another type of reparse
  1377  		// point
  1378  		return -1, ENOENT
  1379  	}
  1380  	n = copy(buf, []byte(s))
  1381  
  1382  	return n, nil
  1383  }
  1384  
  1385  // Deprecated: CreateIoCompletionPort has the wrong function signature. Use x/sys/windows.CreateIoCompletionPort.
  1386  func CreateIoCompletionPort(filehandle Handle, cphandle Handle, key uint32, threadcnt uint32) (Handle, error) {
  1387  	return createIoCompletionPort(filehandle, cphandle, uintptr(key), threadcnt)
  1388  }
  1389  
  1390  // Deprecated: GetQueuedCompletionStatus has the wrong function signature. Use x/sys/windows.GetQueuedCompletionStatus.
  1391  func GetQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) error {
  1392  	var ukey uintptr
  1393  	var pukey *uintptr
  1394  	if key != nil {
  1395  		ukey = uintptr(*key)
  1396  		pukey = &ukey
  1397  	}
  1398  	err := getQueuedCompletionStatus(cphandle, qty, pukey, overlapped, timeout)
  1399  	if key != nil {
  1400  		*key = uint32(ukey)
  1401  		if uintptr(*key) != ukey && err == nil {
  1402  			err = errorspkg.New("GetQueuedCompletionStatus returned key overflow")
  1403  		}
  1404  	}
  1405  	return err
  1406  }
  1407  
  1408  // Deprecated: PostQueuedCompletionStatus has the wrong function signature. Use x/sys/windows.PostQueuedCompletionStatus.
  1409  func PostQueuedCompletionStatus(cphandle Handle, qty uint32, key uint32, overlapped *Overlapped) error {
  1410  	return postQueuedCompletionStatus(cphandle, qty, uintptr(key), overlapped)
  1411  }
  1412  
  1413  // newProcThreadAttributeList allocates a new [procThreadAttributeListContainer], with the requested maximum number of attributes.
  1414  func newProcThreadAttributeList(maxAttrCount uint32) (*procThreadAttributeListContainer, error) {
  1415  	var size uintptr
  1416  	err := initializeProcThreadAttributeList(nil, maxAttrCount, 0, &size)
  1417  	if err != ERROR_INSUFFICIENT_BUFFER {
  1418  		if err == nil {
  1419  			return nil, errorspkg.New("unable to query buffer size from InitializeProcThreadAttributeList")
  1420  		}
  1421  		return nil, err
  1422  	}
  1423  	const LMEM_FIXED = 0
  1424  	alloc, err := localAlloc(LMEM_FIXED, uint32(size))
  1425  	if err != nil {
  1426  		return nil, err
  1427  	}
  1428  	// size is guaranteed to be ≥1 by InitializeProcThreadAttributeList.
  1429  	al := &procThreadAttributeListContainer{data: (*_PROC_THREAD_ATTRIBUTE_LIST)(unsafe.Pointer(alloc))}
  1430  	err = initializeProcThreadAttributeList(al.data, maxAttrCount, 0, &size)
  1431  	if err != nil {
  1432  		return nil, err
  1433  	}
  1434  	al.pointers = make([]unsafe.Pointer, 0, maxAttrCount)
  1435  	return al, err
  1436  }
  1437  
  1438  // Update modifies the ProcThreadAttributeList using UpdateProcThreadAttribute.
  1439  func (al *procThreadAttributeListContainer) update(attribute uintptr, value unsafe.Pointer, size uintptr) error {
  1440  	al.pointers = append(al.pointers, value)
  1441  	return updateProcThreadAttribute(al.data, 0, attribute, value, size, nil, nil)
  1442  }
  1443  
  1444  // Delete frees ProcThreadAttributeList's resources.
  1445  func (al *procThreadAttributeListContainer) delete() {
  1446  	deleteProcThreadAttributeList(al.data)
  1447  	LocalFree(Handle(unsafe.Pointer(al.data)))
  1448  	al.data = nil
  1449  	al.pointers = nil
  1450  }
  1451  
  1452  // List returns the actual ProcThreadAttributeList to be passed to StartupInfoEx.
  1453  func (al *procThreadAttributeListContainer) list() *_PROC_THREAD_ATTRIBUTE_LIST {
  1454  	return al.data
  1455  }
  1456  
  1457  // RegEnumKeyEx enumerates the subkeys of an open registry key.
  1458  // Each call retrieves information about one subkey. name is
  1459  // a buffer that should be large enough to hold the name of the
  1460  // subkey plus a null terminating character. nameLen is its
  1461  // length. On return, nameLen will contain the actual length of the
  1462  // subkey.
  1463  //
  1464  // Should name not be large enough to hold the subkey, this function
  1465  // will return ERROR_MORE_DATA, and must be called again with an
  1466  // appropriately sized buffer.
  1467  //
  1468  // reserved must be nil. class and classLen behave like name and nameLen
  1469  // but for the class of the subkey, except that they are optional.
  1470  // lastWriteTime, if not nil, will be populated with the time the subkey
  1471  // was last written.
  1472  //
  1473  // The caller must enumerate all subkeys in order. That is
  1474  // RegEnumKeyEx must be called with index starting at 0, incrementing
  1475  // the index until the function returns ERROR_NO_MORE_ITEMS, or with
  1476  // the index of the last subkey (obtainable from RegQueryInfoKey),
  1477  // decrementing until index 0 is enumerated.
  1478  //
  1479  // Successive calls to this API must happen on the same OS thread,
  1480  // so call [runtime.LockOSThread] before calling this function.
  1481  func RegEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno error) {
  1482  	return regEnumKeyEx(key, index, name, nameLen, reserved, class, classLen, lastWriteTime)
  1483  }
  1484  
  1485  func GetStartupInfo(startupInfo *StartupInfo) error {
  1486  	getStartupInfo(startupInfo)
  1487  	return nil
  1488  }
  1489  
  1490  func CreateFile(name *uint16, access uint32, mode uint32, sa *SecurityAttributes, createmode uint32, attrs uint32, templatefile int32) (handle Handle, err error) {
  1491  	handle, err = createFile(name, access, mode, sa, createmode, attrs, templatefile)
  1492  	if handle != InvalidHandle {
  1493  		// CreateFileW can return ERROR_ALREADY_EXISTS with a valid handle.
  1494  		// We only want to return an error if the handle is invalid.
  1495  		err = nil
  1496  	}
  1497  	return handle, err
  1498  }
  1499  

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